{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,12]],"date-time":"2026-05-12T16:09:36Z","timestamp":1778602176953,"version":"3.51.4"},"reference-count":18,"publisher":"Walter de Gruyter GmbH","issue":"12","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2025,12,17]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec id=\"j_jpem-2025-0382_abs_001\">\n                    <jats:title>Objectives<\/jats:title>\n                    <jats:p>\n                      Carnitine palmitoyltransferase 1\u202fA (CPT1A) deficiency is an ultra-rare autosomal recessive disorder of the carnitine cycle caused by biallelic pathogenic variants in the\n                      <jats:italic>CPT1A<\/jats:italic>\n                      gene. It mainly presents with a hepatic phenotype and is a target disease of newborn screening programs worldwide. Disease-specific and diagnostic abnormalities of CPT1A deficiency comprise elevated concentrations of free\u00a0carnitine as well as an elevated metabolite ratio [C0\/(C16\u00a0+\u00a0C18)] in blood, but the ideal sample material has been a matter of debate.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec id=\"j_jpem-2025-0382_abs_002\">\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>We present biochemical data of five CPT1A deficient patients, of whom four were diagnosed by newborn screening from dried blood\u00a0spots.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec id=\"j_jpem-2025-0382_abs_003\">\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>Our cases demonstrate that acylcarnitine profiles and especially concentrations of free carnitine can be normal in plasma in infants with CPT1AD at confirmation diagnosis after screening and during follow-up. Even the [C0\/(C16\u00a0+\u00a0C18)] ratio yielded normal results in some\u00a0cases.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec id=\"j_jpem-2025-0382_abs_004\">\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>Our data show, that dried blood is the preferred sample material for the diagnosis of CPT1A deficiency as it is superior to serum\/plasma with respect to diagnostic sensitivity and reliability in quantification of the ratio [C0\/(C16\u00a0+\u00a0C18)]. CPT1A deficiency can be missed, if the analysis is only performed in serum or plasma, and confirmatory diagnostics in serum or plasma after screening can be false negative.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1515\/jpem-2025-0382","type":"journal-article","created":{"date-parts":[[2025,9,29]],"date-time":"2025-09-29T07:56:00Z","timestamp":1759132560000},"page":"1324-1331","source":"Crossref","is-referenced-by-count":0,"title":["Pitfalls in the diagnosis of carnitine palmitoyltransferase 1 deficiency"],"prefix":"10.1515","volume":"38","author":[{"given":"Sarah C.","family":"Gr\u00fcnert","sequence":"first","affiliation":[{"name":"Faculty of Medicine, Department of Pediatrics , 9174 Children\u2019s Hospital, Adolescent Medicine and Neonatology, Freiburg University Hospital , Freiburg , Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Urs","family":"Berger","sequence":"additional","affiliation":[{"name":"Faculty of Medicine, Department of Pediatrics , 9174 Children\u2019s Hospital, Adolescent Medicine and Neonatology, Freiburg University Hospital , Freiburg , Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Friederike","family":"H\u00f6rster","sequence":"additional","affiliation":[{"name":"Medical Faculty, Division of Pediatric Neurology and Metabolic Medicine , Center for Pediatric and Adolescent Medicine, Heidelberg University , Heidelberg , Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Kathrin","family":"Schwarz","sequence":"additional","affiliation":[{"name":"Medical Faculty, Division of Pediatric Neurology and Metabolic Medicine , Center for Pediatric and Adolescent Medicine, Heidelberg University , Heidelberg , Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Eva","family":"Thimm","sequence":"additional","affiliation":[{"name":"Medical Faculty, Department of General Pediatrics, Neonatology and Pediatric Cardiology , University Children\u2019s Hospital, Heinrich-Heine-University D\u00fcsseldorf , D\u00fcsseldorf , Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ute","family":"Spiekerkoetter","sequence":"additional","affiliation":[{"name":"Faculty of Medicine, Department of Pediatrics , 9174 Children\u2019s Hospital, Adolescent Medicine and Neonatology, Freiburg University Hospital , Freiburg , Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Dorothea","family":"Haas","sequence":"additional","affiliation":[{"name":"Medical Faculty, Division of Pediatric Neurology and Metabolic Medicine , Center for Pediatric and Adolescent Medicine, Heidelberg University , Heidelberg , Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Anke","family":"Schumann","sequence":"additional","affiliation":[{"name":"Faculty of Medicine, Department of Pediatrics , 9174 Children\u2019s Hospital, Adolescent Medicine and Neonatology, Freiburg University Hospital , Freiburg , Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"374","published-online":{"date-parts":[[2025,9,29]]},"reference":[{"key":"2026051215122197244_j_jpem-2025-0382_ref_001","doi-asserted-by":"crossref","unstructured":"Bonnefont, J-P, Djouadi, F, Prip-Buus, C, Gobin, S, Munnich, A, Bastin, J. 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